Add alternative Sobol direction numbers to the repo.

Also switching to one of the alternates, as it seems to give
better results than the one I was using before.

src/renderer.rs

@@ -709,12 +709,7 @@ fn get_sample(dimension: u32, i: u32, pixel_co: (u32, u32), seed: u32) -> f32 {
         n if (n - 1) < sobol::MAX_DIMENSION as u32 => {
             let dim = n - 1;
             // Sobol sampling.
-            // We skip the first three dimensions here because it gives better
+            sobol::sample_owen(dim, i, hash_u32(dim, scramble))
-            // results on many scenes for some reason.  This is likely worth
-            // investigating in the future, as it may indicate poor sampling
-            // elsewhere in the rendering pipeline (and skipping the first
-            // two dimensions may just mask it).
-            sobol::sample_owen(dim + 3, i, hash_u32(dim, scramble))
         }
         _ => {
             // Random sampling.

sub_crates/sobol/build.rs

@@ -7,7 +7,7 @@ use std::{env, fs::File, io::Write, path::Path};
 const NUM_DIMENSIONS: usize = 256;
 
 /// What file to generate the numbers from.
-const DIRECTION_NUMBERS_TEXT: &str = include_str!("direction_numbers/new-joe-kuo-5.1024.txt");
+const DIRECTION_NUMBERS_TEXT: &str = include_str!("direction_numbers/joe-kuo-other-3.1024.txt");
 
 fn main() {
     let out_dir = env::var("OUT_DIR").unwrap();